Documents / Report
This Defense Intelligence Reference Document from the Defense Intelligence Agency, dated 23 March 2010, was produced under the Advanced Aerospace Weapon System Applications (AAWSA) Program. It surveys invasive and noninvasive brain-machine interface technologies for controlling external devices without limb-operated interfaces. The technologies covered include EEG, MEG, fMRI, NIRS, and implanted electrode arrays. It concludes that noninvasive electrical monitoring is the most promising near-term approach. In the long term, it favors invasive single-neuron cortical connections that use optical stimulation or chip-based arrays.
“Anderson”1 page
UNCLASSIFIED/ /P9Pl 8ffllil.t.k W£1ii ODIi Y Commercial EEG sensors Mindset, by NeuroSky nia, by OCZ Technology Figure 3. Two Commercially Available EEG Sensors. The Mindset utilizes two sensors, one 1n the right earphone and one for placement on the forehead (what looks like a microphone arm is to be pressed against the forehead). The nia records signals from three sensors on the forehead. In a documented and peer-reviewed study, Popescu and colleagues have shown a system that uses 6 dry electrodes and is 90 percent accurate in operation of a 1-D cursor by untrained subjects. Additionally, a measurement of error rates as a function of number of electrodes show that an increase to 12 electrodes could drop the error rate to around 5 percent, but that additional electrodes much beyond a dozen do not significantly improve the accuracy of their algorithm (Reference 28). MEG MEG-based BMI systems have been shown to be feasible utilizing a subject imagining limb movements for binary decisions (References 29, 30). Future work could improve the methodology to parallel that achieved with EEG; however, there are significant technological hurdles to a field deployment of MEG. The magnetic fields from neural activity are detected with very sensitive devices called superconducting quantum interference devices, or SQUIDs. These detectors are sensitive to the neural activity induced 100 IT (femtoTesla) changes near the scalp. SQUIDS only operate at very low temperatures thus requiring a cryogenic system as well significant detection and amplification electronics. The availability of a cold sink and high vacuum, such as in a space-based application, could reduce the support system overhead, but there is still the matter of the weakness of the signals. Even if future detector development like atomic magnetometers would solve the equipment overhead issue for Earthbound application, the fact that 100 IT is about 100 million times smaller than the Earth's magnetic field will prove an insurmountable barrier to sifting signal from noise in anything but a heavily-shielded, metal-free environment. Attempts have been made to use High-Tc superconductors as a shielding material with some success (Reference 31), but significant further development is needed. 8 UNCLASSIFIEDf)1P9PI 8ffl&I.«1k W£1ii ODIi Y
Not linked to a story yet.
Report, from the dia collection. The PDF is mirrored here; the original link is above. 36 pages are in the text index: search them above, or from the library's search.